Packing for containers made of wound sheet metal



P. M. FONS Dec. 22, 1959 PACKING FOR CONTAINERS MADE OF WOUND SHEET METAL 2 Sheets-Sheet 1 Filed Feb. 19, 1957 Dec. 22, 1959 i s I 2,918,002

I PACKING FOR CONTAINERS MADE OF WOUND SHEET METAL Filed Feb. 19, 1957 2 Sheets-Sheet 2 PACKING FORCONTAINERS MADE OF WOUND SHEET METAL Paul M. Pons, Paris, France, assignor to Forges et Ateliers de Constructions ElectriquesdeJeumont, Paris, France, a corporationof France Application February 19, 1957, Serial No. 641,131

Claims priority, application FranceMarch 21, 1956 1 Claim. Cl. 102-43 This invention relates to packings for containers made of wound sheet material. It is applicable more particularly, but not exclusively, to artilleryshell cases having a tubular portion made of helically wound sheet metal secured to a base, thus having a helical lap joint or seam formed on the external periphery.

The invention has for its principal object to provide a simple, effective and inexpensive means for rendering such containers substantially fluid-tight.

, Another object is to provide a simple method of manufacture, consisting in a particular setting in place of the. packings in question.

It is a feature of the invention that sheet metaltobe wound is folded so as to produce one or more narrow grooves, preferably rectilinear, into which plastic or yieldable material is placed, the grooves and the material contained therein being thereafter compressed in the course of the subsequent shaping of the container.

The invention is hereinafter described with reference to the accompanying drawings, which illustrate diagram matically, by way of example, some suitable embodiments thereof and in which:

Fig. l is a view of the initial shape of a sheet metal to be wound for making a container body in accordance with the invention.

Fig. 2 is a partial sectional view on an enlarged scale, of a groove folded in the sheet in Fig. 1 and filled with plastic material.

Fig. 3 is a view of a transverse section of a tubular portion after the molding operation.

Fig. 4 is a partial longitudinal sectional view showing the lower part of the finished container after compressio of the groove and its contents.

Fig. 5 is a partial longitudinal sectional view of a modification of the shell.

in accordance with the invention, Figs. 1 and 2, a sheet metal 1 having initially the shape shown in Fig. 1 and delimited by two rectilinear edges 1A and 1B is folded either before, in the course of or after its cutting out, at least once so as to produce a narrow groove 3, as shown. The groove 3 may extend between the two curved edges representing the extremities of the tubular portion of a container which will be formed by winding the sheet 1 helically, as shown in transverse section in Fig. 3. It will be understood that in certain cases, however, it will be preferable to make the groove shorter than shown in Fig. 1. Moreover it will be clearly understood that a plurality of grooves may be formed in the sheet 1.

In the groove 3 or in each of the grooves, there is disposed a yieldable thread-like packing element which is made of a plastic material 4, and may consist for example of copper, lead or soft alloy wires, threads of rubber or synthetic resins, braids of textile or other materials, non-hygroscopic but impregnated if desired with a suitable substance. There may likewise be disposed in said grooves a liquid which, in solidifying, will leave therein a thread-like plastic material.

2 As shown in Fig. 3, a fold or groove 3 is formedin at least one of the subjacent layers, preferably the first, of the wound sheet 1. The wound sheet may be secured in the known manner in an annular groove 5 formed in a base 2, as shown in Fig. 4, the inturned end of the tubular portion being clamped in the groove 5 by vertical compression pressure applied to a circular lip 6 over the groove 5. The member 4 is thus disposed in spaced relationship from a. helical seam 1A.

When the container thus constructed is subsequently placed in a mold (not shown) and. subjected to high in ternal pressure with a view to forming it to its final shape, the. fold and the packing 4 contained in the groove 3 are compressed, forming a tight joint between two superposedlayers of the Sheet metal, which ensures the fluid tightness of the sheet helically. wound into a tubular por-.'

tion according to Fig. 3.. I

In order to ensure complete fluid-tightness of thecontairier, the construction shown inFig. 5 may be usedwhere there is shown the lower part of a shellcase before the inturned end of the helically woundsheet metal 1 is secured to the base 2. The outer edge. of the sheet defining the seam is represented by a dotted line at 1B.

At the level wherev the tubular sheet metal 1- is turned. into the frusto-conical groove 5 of the base 2, the outer edge of the base is beveled and is thus slightly shortened so as to reduce its height as shown at 9. Thus between the inturned end of the tubular portion and the edge of the base at 9 a circular throat or recess is formed into which there is introduced a packing ring 8 made of deformable material. This ring having a small cross section as shown in Fig. 5 may be of a smaller diameter than the tubular portion and is forced down vertically over the tubular portion in order to lodge in the throat or recess. It will be seen that its section may be circular as shown, triangular or some other configuration.

The base 2 along with the tubular portion formed by the wound metal sheet 1, and the ring '8 are shown surrounded by a collar 7 of the tubular shape shown and described in the co-pending Leon Heidmann application, Serial No. 596,743, filed July 9, 1956.

The shape and the dimensions of this collar 7 are chosen in such a way that after the tubular portion has been clamped in a known manner by vertical compression of the lip 6, and in the course of the customary moulding of the sheet 1 by high internal pressure, the tubular portion of the shell case when expanding in the mold, presses itself against the collar 7, thereby compressing the ring 8 between the sheet metal 1 and this collar, so as to ensure the tightness of the joint.

Moreover, the fold which is made on the sheet 1 to produce the grove 3 and filled with a plastic material 4 as mentioned above, is preferably arranged helically or obliquely so as to reach the outer edge 1B of the sheet metal in the interior of the collar 7, and near the ring 8. It follows that there is contact and cooperation between the material 4 which is forced out of the extremity of the groove 3 and the material of the ring 8, flattened by the molding. Accordingly there is thus obtained an uninterrupted fluid-tight joint which protects the interior of the shell case against penetration of moisture and dampness encountered in operations in the field.

It can be seen that there may be provided in the sheet metal several folds producing two or more grooves 3 some of which may be non-rectilinear, so as to reach the edge 1B of the sheet at a favorable angle.

It will be understood that the embodiments of the invention shown may be modified in various ways without departing from the scope of the invention as defined by the appended claim. It is likewise to be understood that the invention may be combined with suitable means for ensuring the tightness of the inturned end of the v tented. De 22 .5 .5.3,

formable material having on one face a frnsto-conical first groove, a multi-layer tubular portion consisting of a winding of deformable sheet material having overlapping marginal edge portions so as to form an external helical lap seam, one end of said tubular portion being frust-conical and fastened in said frusto-conical groove to join the tubular portion and the base, the other end of said tubular portion being free, said base having a peripheral shoulder at an end opposite said face and a bevelled surface disposed between the periphery of the base and said face having the frusto-conical groove thereby to form in cooperation with said tubular: portion a narrow peripheral recess adjacent said face, means to seal the lap seam and make it fluid-tight comprising a plurality of inwardly directed registering folds on said tubular portion extending longitudinally thereof so as to form registering depressions on the inner layers only and so as to form at least one narrow second groove in an inner layer immediately adjacent the outside layer, at least one yieldable thread-like packing element disposed in said second groove, said second groove being positioned a selected distance from the lap seam at least along a portion of the length of the seam so that the packing element seals said lap seam to make the shell case substantially fluid-tight at said seam, a short cylindrical collar positioned on said shoulder and encircling the tubular portion, the collar being superposed over an area where the tubular portion and the base are fastened, an exterior annular yieldable packing ring having a small cross section disposed in said recess under compression by the collar against the tubular portion and the base, and at least one of said thread-like packing elements disposed in said second groove being positioned at a predetermined angle relative to the seam and terminating at said helical seam so as to reach said packing ring, whereby said shell case is made fluid-tight at the helical seam and between the tubular portion and the base.

References Cited in the file of this patent UNITED STATES .PATENTS 42,329 Crispin Apr. 12, 1864 2,193,573 Tackler Mar. 12, 1940 2,397,206 Ryan Mar. 26, 1946 2,397,370 Raven et al Mar. 26, 1946 2,398,788 Hedrick Apr. 23, 1946 2,445,268 Hodgins July 13, 1948 2,481,357 Smith et al Sept. 6, 1949 2,829,595 Hitchens Apr. 8, 1958 2,853,945 Stealey Sept. 30, 1958 FOREIGN PATENTS 731,749 Germany June 3, 1943 731,747 Germany June 4, 1943 731,748 Germany June 7, 1943 574,966 Great Britain Jan. 29, 1946 

